Vladis Kosse’s research while affiliated with Queensland University of Technology and other places

In South and Southeast Asia, postharvest loss causes material waste of up to 66% in fruits and vegetables, 30% in oilseeds and pulses, and 49% in roots and tubers. The efficiency of postharvest equipment directly affects industrial-scale food production. To enhance current processing methods and devices, it is essential to analyze the responses of food materials under loading operations. Food materials undergo different types of mechanical loading during postharvest and processing stages. Therefore, it is important to determine the properties of these materials under different types of loads, such as tensile, compression, and indentation. This study presents a comprehensive analysis of the available literature on the tensile properties of different food samples. The aim of this review was to categorize the available methods of tensile testing for agricultural crops and food materials to investigate an appropriate sample size and tensile test method. The results were then applied to perform tensile tests on pumpkin flesh and peel samples, in particular on arc-sided samples at a constant loading rate of 20 mm min(-1). The results showed the maximum tensile stress of pumpkin flesh and peel samples to be 0.535 and 1.45 MPa, respectively. The elastic modulus of the flesh and peel samples was 6.82 and 25.2 MPa, respectively, while the failure modulus values were 14.51 and 30.88 MPa, respectively. The results of the tensile tests were also used to develop a finite element model of mechanical peeling of tough-skinned vegetables. However, to study the effects of deformation rate, moisture content, and texture of the tissue on the tensile responses of food materials, more investigation needs to be done in the future.

At present, for mechanical power transmission, Cycloidal drives are most preferred - for compact, high transmission ratio speed reduction, especially for robot joints and manipulator applications. Research on drive-train dynamics of Cycloidal drives is not well-established. This paper presents a testing rig for Cycloidal drives, which would produce data for development of mathematical models and investigation of drive-train dynamics, further aiding in optimising its design.

Car carriers are a type of semitrailer which exhibit Occupational Health and Safety (OHS) concerns due to falls from height during operations. This paper outlines research carried out on the car carrier sector to prevent hazard due to falls. A new design addresses OHS concerns of falls from height. Injuries are often caused by drivers working above 1.5 m height for loading-unloading of cars, moving decks up and down and strapping cars in. The new car carrier design excels in reducing the risk of injuries to drivers and represents a new bench mark for OHS standards in the heavy vehicle sector. The next step would be to transfer this technology to other similarly affected heavy vehicle sectors.

Peeling is an essential phase of post harvesting and processing industry; however the undesirable losses and waste rate that occur during peeling stage are always the main concern of food processing sector. There are three methods of peeling fruits and vegetables including mechanical, chemical and thermal, depending on the class and type of fruit. By comparison, the mechanical method is the most preferred; this method keeps edible portions of produce fresh and creates less damage. Obviously reducing material losses and increasing the quality of the process has a direct effect on the whole efficiency of food processing industry which needs more study on technological aspects of this industrial segment. In order to enhance the effectiveness of food industrial practices it is essential to have a clear understanding of material properties and behaviour of tissues under industrial processes. This paper presents the outlines of research that seeks to examine tissue damage of tough skinned vegetables under mechanical peeling process by developing a novel FE model of the process using explicit dynamic finite element analysis approach. In the proposed study a nonlinear model which will be capable of simulating the peeling process specifically, will be developed. It is expected that unavailable information such as cutting force, maximum shearing force, shear strength, tensile strength and rupture stress will be quantified using the new FEA model. The outcomes will be used to optimize and improve the current mechanical peeling methods of this class of vegetables and thereby enhance the overall effectiveness of processing operations. Presented paper will focus on available literature and previous works have been done in this area of research.

Mechanical damages such as bruising, collision and impact during food processing stages diminish quality and quantity of productions as well as efficiency of operations. Studying mechanical characteristics of food materials will help to enhance current industrial practices. Mechanical properties of fruits and vegetables describe how these materials behave under loading in real industrial operations. Optimizing and designing more efficient equipments require accurate and precise information of tissue behaviours. FE modelling of food industrial processes is an effective method of studying interrelation of variables during mechanical operation. In this study, empirical investigation has been done on mechanical properties of pumpkin peel. The test was a part of FE modelling and simulation of mechanical peeling stage of tough skinned vegetables. The compression test has been conducted on Jap variety of pumpkin. Additionally, stress strain curve, bio-yield and toughness of pumpkin skin have been calculated. The required energy for reaching bio-yield point was 493.75, 507.71 and 451.71 N.mm for 1.25, 10 and 20 mm/min loading speed respectively. Average value of force in bio-yield point for pumpkin peel was 310 N.

Virtual prototyping (VP) is more commonly used alternative to rapid prototyping (RP) to validate products without substantial investments. This article covers recent advancements in VP technologies to accommodate kinematics and use them to evaluate functional aspects of automotive designs. Traditionally to validate effective function of the product, prototypes were constructed in the earlier stages of design. These prototypes were used to validate design functions of new products. Subsequently products were launched for production runs after corrections were made for issues found during prototyping stages. VP techniques use advancements in software tools to mimic the physical prototyping of product. The new advancements of using function parameters in soft tools added new paradigm in VP techniques. Kinematics with function parameters such as load conditions, motions are added using force (F) and motion (M) functions in design scenario. Kinematics used in virtual environment uses positions, velocity, acceleration, inertial forces, and power requirements, of all the components in mechanisms to recreate virtual effect on the models. Comprehensive engineering designs are produced reducing product design cycle by saving time, costs in set ups and manufacturing the physical prototypes. This extension of virtual design process for physical sampling is unique and was developed, implemented successfully in automotive design application. In this paper experimental study conducted on a car carrier, which is developed under authors responsibility has been used to illustrate VP techniques.

An important aspect of designing any product is validation. Virtual design process (VDP) is an alternative to hardware prototyping in which analysis of designs can be done without manufacturing physical samples. In recent years, VDP have been generated either for animation or filming applications. This paper proposes a virtual reality design process model on one of the applications when used as a validation tool. This technique is used to generate a complete design guideline and validation tool of product design. To support the design process of a product, a virtual environment and VDP method were developed that supports validation and an initial design cycle performed by a designer. The product model car carrier is used as illustration for which virtual design was generated. The loading and unloading sequence of the model for the prototype was generated using automated reasoning techniques and was completed by interactively animating the product in the virtual environment before complete design was built. By using the VDP process critical issues like loading, unloading, Australian Design rules (ADR) and clearance analysis were done. The process would save time, money in physical sampling and to large extent in complete math generation. Since only schematic models are required, it saves time in math modelling and handling of bigger size assemblies due to complexity of the models. This extension of VDP process for design evaluation is unique and was developed, implemented successfully. In this paper a Toll logistics and J Smith and Sons car carrier which is developed under author’s responsibility has been used to illustrate our approach of generating design validation via VDP.

Purpose: In this paper we discuss the innovative curriculum structure, teaching and learning approaches ofcoherent delivery of manufacturing in conjunction with engineering design and materials from year one to yearfour, including specializations, real life projects and final year projects.Design/methodology/approach: Tertiary institutions now face serious challenges. Modern industry requiresengineering graduates with strong knowledge of modern technologies, highly practical focus, managementskills, ability to work individually and in a team, understanding of environmental issues and many other skillsand graduate attributes. Institutions in the tertiary sector change courses and modify curriculum to reflectchallenges of the modern industry and make engineering graduates better prepared for the “real world”.Findings: Queensland University of Technology, in response to industry requirements has re-designed theengineering curriculum with some integrated units. An integrated approach was adopted for the teaching ofMaterials Manufacturing and Design. This is further strengthened by various forms of final year projects. Thisincludes industry based CEED projects as well as SAE Formula A Motorsport.Practical implications: Queensland University of Technology in the recent years introduced an innovativestructure of engineering courses with a common core for Bachelor of Engineering Mechanical, Infomechatronicsand Medical, where manufacturing is taught in conjunction with engineering design and engineering materials.Originality/value: Students survey indicates that the integrated approach enhances their learning and that theindustry based projects help them to be better prepared for graduate work as well improving their communicationskills.

Machine condition monitoring (MCM) of low speed machinery is highly challenging task. Methods of MCM of machinery operating at a speed of 500 to 3000 rpm are well-developed including wear debris and vibration monitoring (both instrumentation and signal processing). Machinery operating at a speed below 500 rpm is usually grease lubricated and wear debris analysis cannot be effectively used. Monitoring of vibrations at such speed is very difficult because conventional accelerometers give very week signal especially at a speed below 100 rpm. There is a vital need to develop new approaches to monitoring fault development on low speed machinery, which include new sensors and alternative methods such as sound emission and ultrasonic emission. Essential part of this process is development of testing facilities that enable modeling of different combinations of loading conditions that take place on low speed machinery and verify new MCM methods. For this purpose a design study has been conducted to develop methods of modeling of different combinations of loads on bearings and gears operating at low speed. This study resulted in the development of a unique highly versatile test rig presented in this paper. It enables modeling of different types of bearings operating at a speed of 30 to 600 rpm under a combination of different loading conditions, in particular, steady load, impact load, swinging load, axial load and rumble. It also enables modeling of transitional processes in shaft-mounted, flange-mounted and foot-mounted gear drives under different loading conditions (start up, coast down, increase or decrease of speed). Special instrumentation enables monitoring of the supply frequency, phase current, power consumed and taking these parameters for recording.